1. Field of the Invention
The present invention relates to electrical plugs and sockets for connecting and disconnecting electronic devices.
2. Description of the Related Art
A plug and socket are mating electrical connectors used to supply electrical power to an electronic device, such as a computer or home appliance. An electrical plug is typically a male electrical connector included with the electronic device that removably “plugs into” a female socket to receive electrical power from the socket, such as in the form of alternating current (AC) or, less commonly, direct current (DC). Terminals on the plug (i.e. “plug terminals”) mate with terminals on the socket (i.e. “socket terminals”) when plugged in. Plug terminals are usually male, and male plug terminals may be pins, prongs, blades, or combinations thereof. A plug with male terminals mates with a socket having a corresponding arrangement of female terminals. When the plug terminals are inserted into the socket holes, the plug terminals are placed in electrical contact with electrical “socket terminals” within the electrical socket. The socket terminals on a female socket may be referred to herein as female terminals, because these terminals are associated with the holes of the socket, even though the terminals may not themselves form a female socket. Though the male plug is generally fixed to an electrical device or appliance and the female socket is typically fixed, such as being secured to a wall, the reverse configuration is also possible.
An electrical socket is energized with electricity, such as from a commercial power supply or electrical generator, so that electric power can flow from the socket to an electronic device plugged into the socket. The electrical socket may be a “wall socket” included within a wall outlet of a building, for example. Other devices, such as PC battery-backup devices and power strips, plug into an electrical socket such as a wall socket, and include multiple on-board electrical sockets that receive electrical power from the wall socket. Yet another type of electrical socket may be included directly on an electronic device for daisy-chaining with additional electronic devices. For example, in a component stereo system, a primary audio component such as an audio receiver may include both a plug for plugging-into and receiving power from a wall socket or power strip, and one or more on-board electrical sockets that are wired to transfer some of the current from the wall socket or power strip to additional audio components plugged directly into the on-board electrical sockets. Other configurations of electrical sockets and mating electrical plugs are also known in the art.
One drawback of conventional plugs and sockets is the risk of exposure of the user to electrical shock, especially while the user plugs-in (connects) or un-plugs (disconnects) an electronic device. In particular, the plug terminals on a male plug typically extend directly from a plug body that the user grasps when plugging-in the device. Thus, the male plug terminals are typically exposed, and the user's fingers can be dangerously close to the male plug terminals when holding the plug body. When the electronic device is plugged in, the plug terminals contact the socket terminals prior to full insertion of the plug terminals into the socket holes. Likewise, when the electronic device is unplugged, the plug terminals may remain in electrical contact with the socket terminals until the plug terminals have been nearly fully removed from the socket holes. Thus, the plug terminals are energized for at least a portion of the movement of the plug with respect to the socket when either plugging-in or un-plugging an electronic device. The user risks electrical shock by inadvertently contacting the plug terminals with the user's fingers while the user is plugging-in or unplugging the electronic device.
The complications of conventional plugs and sockets are compounded in the case of power strips, which are usually loose rather than being fixed to any particular surface. Thus, to unplug an electronic device from a power strip, the user must usually hold the power strip while removing the plug. The tendency is for the user to hold the power strip with one hand while pulling on the plug with the other hand. This maneuver places both hands in potentially-dangerous proximity to electrically energized plug terminals of the device being unplugged, to electrically energized plug terminals of another device, or to open female socket terminals. Aside from the risk of shock, the process of removing a plug from a power strip may be cumbersome, as well. If the power strip is placed under a desk or other location with limited access and/or limited lighting, it can be difficult for the user to access the power strip with both hands. Some users might even be tempted to step on an edge of the power strip to hold it while pulling out the plug, which is also not ideal.
A solution is desired for improved connection of an electronic device to an electrical socket, particularly in view of the above limitations in the prior art plugs and sockets. For example, an apparatus that makes plugging-in and un-plugging a device easier and/or safer is desired. It would be advantageous if such a solution did not require any direct redesign of the electronic device, so that, for example, an electronic device having a conventional plug could still be coupled to and powered by an electrical socket using the proposed solution.